Protease Power Strokes Force Proteins to Unfold
نویسندگان
چکیده
ATP-dependent proteases degrade proteins in the cytosol of cells. Two recent articles, by Aubin-Tam et al. (2011) and Maillard et al. (2011 [this issue]), use single-molecule optical tweezers to show directly that these molecular machines use the energy derived from ATP hydrolysis to mechanically unfold and translocate its substrates into the proteolytic chamber.
منابع مشابه
ClpX Shifts into High Gear to Unfold Stable Proteins
Protein degradation by the ClpXP protease requires collaboration among the six AAA+ domains of ClpX. Using single-molecule optical tweezers, Sen et al. show that ClpX uses a coordinated succession of power strokes to translocate polypeptides in ATP-tunable bursts before reloading with nucleotide. This strategy allows ClpX to kinetically capture transiently unfolded intermediates.
متن کاملDissection of Axial-Pore Loop Function during Unfolding and Translocation by a AAA+ Proteolytic Machine.
In the axial channels of ClpX and related hexameric AAA+ protein-remodeling rings, the pore-1 loops are thought to play important roles in engaging, mechanically unfolding, and translocating protein substrates. How these loops perform these functions and whether they also prevent substrate dissociation to ensure processive degradation by AAA+ proteases are open questions. Using ClpX pore-1-loop...
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ATP-dependent proteases are vital to maintain cellular protein homeostasis. Here, we study the mechanisms of force generation and intersubunit coordination in the ClpXP protease from E. coli to understand how these machines couple ATP hydrolysis to mechanical protein unfolding. Single-molecule analyses reveal that phosphate release is the force-generating step in the ATP-hydrolysis cycle and th...
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ورودعنوان ژورنال:
- Cell
دوره 145 شماره
صفحات -
تاریخ انتشار 2011